Shogakukan founded Shueisha which founded Hakusensha. These three separate companies, are together called the Hitotsubashi Group, one of the largest publishing groups in Japan. Shogakukan is located at Hitotsubashi, Chiyoda, Tokyo, and the other two companies are located in the same ward.
Shogakukan in the US
Shogakukan's licensing arm in North America was ShoPro Entertainment; it was merged into Viz Media in 2005.
Shogakukan's production arm is Shogakukan Productions Co.,Ltd. (now Shogakukan Shueisha Productions)